System for the transmission of electrical energy.



0. n. LANNING. I SYSTEM FOR THE TRANSMISSION OF BLEQ'I'BIGAL ENERGY.

APPLICATION FILED um s, ieo'l.

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Patented Sept; 5,1911. b

v I by G. D. LANNING.

SYSTEM FOR THE TRANSMISSION OF BLEGTBIGAL ENERGY. APPLICATION FILED AUG, 8, 1901/ Patentd Sept. 5, 1911;

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SYSTEM FOR THE TRANSMISSION OF ELEGTRIGAL ENERGY. N APPLICATION FILED AUG. 11, 1907.

1,002,711. Patented Sept. 5,1911.

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witnesses: Invntor: flWj/qfi W CharlesDlIann/mg,

v 0. D. LANNING.

SYSTEM FOR THE TRANSMISSION OF ELECTRICAL ENERGY.

APPLIGATION FILED AUG. 8, 1907.

1 ,0Q2,71 1 Patented Sept. 5, 1 911.

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witnesses I nvento'r am y 'ChQrZQQDZanm'ng, (gag/WA V 7 Attyg witnesses; 1

D. LANNING.

SYSTEM FOR THE TEANSMISSION OF ELECTRICAL ENERGY.

APPLIUATIQN IILIBIJ AUG. 8, 1907.

8 SHEETS-$311331 6.

Inventor Attys.

c. 1). 11111111111}. SYSTEM FOR THE TRANSMISSION OF ELECTRICAL ENERGY.

' APPLICATION FILED AUG. 8, 19!)? 1,002,711. Pa en ed Sept. 5,1911;

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witnesses j Inventor:

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'0. 11. LANNING. SYSTEM FOR THE TRANSMISSION OF ELECTRICAL ENERGY. APPLICATION TILED AUG. 8, 1907.

1,002,71 1 Patented Sept. 5, 1911.

1 i I a BIIEFTQ-BHEET 7" 1280 @f' 6 'Q I 0. 1). LANN ING. SYSTEM FOR THE TRANSMISSION OF ELECTRICAL ENERGY.

APPLIUATION FILED AUG. 8, 1907- 1,002,71 1, Patented Sept. 5, 1,911.

8 SHEETS- 831 B.

Wii'nessea; M n

s-ion of Electrical Energy,

UNITED STATES PATENT OFFICE.

CHARLES LANNING, OF BOS'I'OIN', MASSACHUSETTS SYSTEM FOR THE TRANSMISSION OF ELECTRICAL ENERGY.

Specification of Letters Patent.

Application filed August 8, 1907. Serial No. 387,647.

like letters on the drawings representing.

like parts. V I My invention relates to the transmission of'electrical energy, being more particularly concerned with the reinforcement of transmitted energy.

While my invention may have extensive and varied applications, it possesses particular advantagesin connection with the art of electrical telephony, and I have therefore .20 described and illustrated orie embodiment thereof in connectionwith an improved tele phonic relay or repeating device.

.In telephone relays, unless some circult changing means is provided for controlling the circuits and establishing them accurately with reference to the desired direction of speech-transmission, the reactive effect of themlosely associated circuits which is a necessary consequence of a two-way repeater constructed under such limitations, results in a reactive noise efi'ect of the associated circuits upon each other or in a conflict and distortion of the voice currents flowing therein. v

Circuit changing or switching devices heretofore employed in two-way repeater systems have depended for their operation upon forces extraneous to the'usual teleonic currents and have not been automat1c.

" When employed 1n connection with a two- Way repeater my invention automatically particularly pointed out in the appended accomplishes the correct circuiting at a repeating point so as to maintain the desired current strength and at the same time eliminate reactive noise effects.

My invention will be best understood from the following description andaccompanying illustration of one specific embodiment thereof, while its scope will be more claims.

' In the drawings: Figure 1 represents diagrammatically one iform'of circuit arrangement for carrying out my invention; Fig. 2 shows" the relay controlling switch of Big.

the switch shownin for repeating in the instrumentahties v comp 1 in side elevation; Fig. 3 shows an end elc vation of the same; Fig. 4 shows in side elevation the switch controlling magnets and their supports, and the switch lever in cross-section; Fig. 5 is a perspective view of the pivotal support for the switchlever shown in Fig. 1; Fig. 6 shows a modified arrangement of circuits; Fig. 7 is a view similar to Fig: 8 of the switch lever shown in Fig. 6; Fig. 8 is another modified arrangement of circuits; Figs. 9 and 10 are fragmentary'side elevational and cross-sectional views of the form of switch lever represented in Fig. 8; Fig. 11 is a diagrammatic View showing still another arrange- '-ment of+circuits by which my invention may be carried out; Fig. 12 is adetail elevation partially in section of the adjustable switch operating magnet shown in Fig. 11; Fig.

13 is a plan view of the same; Fig. 14. is'a ,detailpartially. in section of the switch lever represented in Fig. 11; Fig. 15 is a diagrammatic view showing an improved arra gement of tapper circuits for the sys: tem own in Fig.'11; Fig- 16 is a detail partially in section of my improved-coherer with its actuating coil; Fig. 17 is a view showing diagrammatically another arrangement of circuits embodying still a different form of myinvention; Fig. 18 is a Patented Sept. 5, 1911 similar but somewhat modified diagram-- matic View; Fig. 19 is a plan view of an improved form of circuit controlling switch; Fig. 20 is a central section in elevation partiallyi broken away, and on an enlarged scale, showing the construction of switch illustrated in Fi 17 Fig. 21 is a.

detail of the connection between the switch arm and its controlling spring; Fig; 22 is a diagrammatic arrangement of circuits which may be'employ ed in connection with a similar but somewhat modified diagrammatic view.

,- Referring to the drawings and to the eniig.' 19; and Fig. 23 is bodiment. of my lnvention which is there.

illustrated, the same contemplates theemployment of -one or more relay or repeating instruments, through which sound undula-.

-tions will be conveyed bet-weemtwo lines in either direction desired.

In the illustrated embodiment of the ini vention the sound-caused electric impulses themselves act-to set the relay connections deiireddirection, the

g 4 electro mag.

netic means embraced in normally complete .line circuits, two-way relaying connections between the two line circuits, and a con-- trolleruol? said relay connections subject to the influence of said elect-ro-magnetie means so that current stren gth in the talking line effects completion oi relaying connections for, repeating to the other line. In the use of the term electromagnetic means not only are the usual magnetic effects upon common and polarized armatures contemplated, but also the repellent effects of alternating current magnets upon appropriate material, preferably copper, in suitable form, known technically as electro-inductive repulsion. I

Referring to Fig. 1, 1 and 2 represent the two sides of a line circuit intended for the transmission of electrical energy in any form. In this:particularinstance I will describe the same as a telephonic circuit and I have, therefore, indicated conventionally at the induction coils, the secondaries 5 and 5 motion and insuring accurate and uni- "-6 and 6 respectively" The other ends of 3 a telephone station which it is to be understood is adaptcd'both for the transmission and the receipt of telephonic voice-actuated currents. The station 3 is shown as connected with a supposedly distant st-at-ion3' having circuits and connections similar and corresponding to those of the station 3.- The stations are provided with the usual battery circuitincluding the primaries 4 and 4 of of which (in the system shown in Figs. 1

and 6) have corres onding'ends onnected by conductors 2'an 2' with binding posts said secondaries are connected by conductors 1 and 1 with electro-magnets 7, 7, respec ti'vely, said magnets beii'g here shown (that is, in Figs. 1 and 6) as of the horse shoe type with double poles confronting each other.

One and of the lever 8 is positioned between said confronting double poles and is faced on each side with para-magnetic material so that this end of the lever will pro-' vide an armature for each magnet. Conductors, 9 and 9 connect the said magnets respectively-with springs 10 andlO secured to the said lever on opposite sides thereof with interposed insulation. may contact normally with pins Hand 11, respectively, mounted'in posts 12 .and 12 and are connected by conductors 13 and 13 with the binding posts 6" and 6 respectively. The-latter are connected by conductors 14 and l y'with an electro-magnet 15 which constitutes the receiver of the repeating instrument, here conventionally shown as of the'balanced type. The transmitter 16 of which is tionnected lay-conductors 20 and 21 with bindin-g posts 22 and. 23 respectively.

Said springs Conductors 24 and 25 lead from said binding posts 22 and 23 to pins 26 and 27 respectively (Fig. 23) mounted in a post 28 and insulatcd from each other. (londimtors 2L and 25 lead from the same binding posts 22 and 23 respectively to pins 26 and 27 mounted in a post 28 and insulated from each other.

The lever 8 extends between the two pairs of pins 26, 27 and 26, 27' and carries at one side a pair of springs29 and 30, and on the opposite side forcontact with the pins 26 and 27 respectively a similar pair ofsprings 29 and for contact with the pins 26' and 27 respectively, said springs being insulated from each other and from the lever.

The conductors 31 and 32 lead from the springs 29 and 30, respectively, and connect with conductors 2 and 1, respectively; and conductors 31 and 32 lead from the springs 29 and 30, respectively, and connect with together at right angles to each other by 'cross piece 35 to which said lever is secured,

the said resilient bars being fastened'to supporting posts 36 and 37-. The pivot pm, of this lever is in the line of intersection ofthe resilient bars and this form of pivoting means, is adopted because of its obviating the latter being .jpurnaled in suitable bearings upon. a'base' idfi I In the'balanced posit-ion of the leverthe springs 29, 30 and 29", 3Q; are removed from contact with the pins 26, 27 and 26, 27, while eachinductive line circuit is completed by contact between the springs 10- and 10 and the pins 11 and 11. 4

When sound undulations are imposed upon either of these circuits, -the electro-- magnets 7 or 7 of the circuit overcomes the balance of the lever- 8, and, by attracting one end of the latter, effects interruptionof the circuit of the other line through the ,opposedelectromagnet by breaki'n the con- T tact between the spring 10 or 1 and the 'postll or 11- and at the same time one of the pairsof springs 29, 30 or 29, is.

brought into contact with one of the pairs.

' ofins 26, 27 or 26, 27', thus completing an in uct-ive relay jtran smittin g circuit in the line which 15191808118 the repeated sound undulations, When talking ceases at one temporarily to pass out from r the alternating magnetic flux,

voice at the transmitting end.

end of the system and is taken up at the other end a reversal ofthe relay connections is eltertedso that sound undulations will be repeated in the opposite direction to what they were before.

The mounting and construction of the switch lever, as described and shown, provides a vibratory circuit controller, namely, the lever 8 having a very low natural rate of vibration and lower, in fact, than that of the lowest audible tone of the human voice,

- such an arrangement is illustrated in Fig. 6.

and the pins 26 and Here electro-magnets 41 and 41 ofthehorse shoe type are incorporated in the connections between the binding posts 22 and 23 lever 8 I is extended.

tween said double poles. as shown at 42 and gm'agnet. n will be are faced on-each side with para-magnetic material so, asto provide an armature for each seen that whena relay transmitter is completed by contact between the springs 29, 30 or 29, 30', and the pins.24,

25 or 24:,25', one or the other of the magnets 41 or 41 will cooperate with the magnet 7 or' 7 maintaining the lever in the position to which it. has been brought by the latter so long as sound undulations continue 1n theline embracing th'esame.

' efiect being in contra-distinction to a In Figs. 8-10 I have shown another form which the details of'circuitconnections and contacts may assume. In this form the switch lever is actuated by the repulsive efl'ect of the alternating magnetic field on the induced current in the copper ring, such well-known in experimental science .and beingelectric rather than mag- --"netic when the latter term is restricted to the action of the magnetic field-on para-mag materials. Accord ingly the magnetic repulse ring and current are so arranged as to establish and maintain the appropriate relay connections by the repulsion of the. lever or circuit controller ttraction thereof, as in the other formshown. Afurther difi'erencein arrangement is shown in that .there is but one set of make and break contacts for the establishment of the relay transmitter circuit. Furthermore, two independent repeatin for talking oppositely from the other,

ilk-002,711

in establishing 26f 'respectivelywvith the double poles of said magnets confronting each-other, and the instrumeilts are employed circuited but governed by the same circuit controller. This is of advantage in avoiding split or divided circuits or possible weakening of currents.

The magnets 43, 43 of the inductive telephonic line circuit are here shown as of the single pole type, and the conductors 44, 45 and 44, 5 leading to them from the-sec on'daries 5 and 5 cross over so thatthe line on one'side of the switching lever 46 con- 'nects with the magnet onthe opposite side thereof Contact springs 47, 47 are mounted upon the switching lever, as in the previously described't'orin, the spring 47 connecting with the magnet 43 by'conduc-, tor 48, and the spring 47' with the magnet $3 by the conductor as. The receivers of the two repeating instruments are shown as single pole magnets 49 and 49 connected respectively by conductors 50 and 50 with the secondaries 5 and 5', and b conduc tors 51 and 51 with'the contact pins 52 and 52. The transmitter of these repeating instruments are shown conventionally at 53 and 53 in local battery circuits 54 and .54 with primaries 55 and 55 of inductive coils. The secondaries 56 and 56. have corresponding ends connected by conductors 57 and 57- with the line conductors 45 and 45 respectively. The other ends of said, secondaries are connected respectively by conductors 58 and 58 with juxtapositioned sin le pole electro-magnets 59 and 59!, which are, in turn, by conductors 60 and 60 with contact pins 61' and 61. single pair of springs 62 and 62' 'norn 1-ally out of contact with said pins respectively,

connected respectively 100 The switching lever carries a t and conductors 63 and 63' connect the springs with the line conductors 4 1 and 44:

respectively.

The switching lever 46 is pivoted intermediate its end, and one end extends between the magnets 43 and 43, other between-the magnets 59 and 59', ing equipped copper rings. The two rings 64, 64at one end are -mounted at opposite sides of the lever, so as to face the magnets l3 and 43, respectively, in concentric relation to the poles thereof, and the two rings 65 and'tirfi at the other end of the leverare similarly disposed with relation to the magnets 59 and .59. Details ofconstructionan respect to the mounting or the rings are illustrated in Figs. 9 and 10, wherein reference nirmerals 66, 66' designate ring-supports ofspider form fastened, to opposite sides of the lever with proper insulation.

It will be seen that with the above described tormof apparatus reversals in the relay connectionswill be automatically effected in the manner hereinbefore explained at each end with a pair of.

and at the with reference to the other forms or em" Tdescribedmontrolbf the relaying. switch is ever, being repellently instead of attractively actuated, and two separate and independent repcating instruments being em ployed for the two directions of trans 5 mission of speech.

It is to be particularly noted that the system of my invention operates in a strictly automatic manner, no manipulation of keys or other means heing'required in order to effect reversals in the relay connections. It' is further tovbe noted that the inductive line circuits are normally completcd and no interruption in the sending line is required in ,order' to set the relay con- .nections for repeating sound undulations in the receiving line.

While preferably both relay secondary circuits are normally in a broken state and the appropriate one is made by effecting the proper contact as above set out, thus completing the line, yet the same result may -be accomplished by having both said circuits as well as those leading to the re lay normally completeand kept so, the establishment and maintenance of the proper circuits as desired to transmit-speech, being effected by increasing pressure to'promot-e conductivity b'tween the appropriate contacts-and decreasing pressure to reduce conductivity between the reciprocal contacts, by the same means in substantially}; the same manner as herein'before explained without, actually breaking any contact. In such case the material used atcontact points might be of any appropriate sort such as platinum, or perhaps carbon. It is apparent that the armature carried by and communicating power to the cir cuitcont-rolling device to move the same may be polarized so as to secure greater responsiveness to the stationary magnet or magnets. s y In lieu of the-lever any approved form oflsuspended" or otherwise movably' maintained circuit controlling. device may be adopted, the necessary delicacy {of arrange- I ment being accomplished by use of arts. v "In theembod-iment ofImy invention above effected by electromagnetic means excited directly through the pulsations of the voicecaused-" f'urrents. -In Figs. 11-16'If have illustrated a modification similar to: the above described form, employing," however electrqsfinagnetic switch; actuating means excited. "by (the voiceicaused currents and through the interposition of a'sensitive' re sponding device, such, for example,-as some form'of-QQherer; t

' Referringaparticula-rly,toiFig. 1 1 the-line 1, passes" 'th roughf -thcjf'primary of the; stepdown-transformer 67 and thence to the bindi g' P s 68;:tri ec ric q p anyof the, well known means employed in.al1ed 'i fi'orwheirthe magnet. is again deenergi'zed.

preferably by a flexible conductor with the spring contact 69 carried by, but insulated from, the pivotally mounted switch 70. The conductor 2 passes through the primary oi the step-downtransformer 71 to the hind ing post 72, the latter beingfadapted to contact with the switch contact 69 through the adjustable contact screw 73, thereby completing the circuit from the station 8. A branch 74 connects the side of the circuit 1, 75 2 through the secondary of the step-up transformer 75 with the adjustable contact screw 76, the latter being adapted upon suitable movement of the switch YO to make contact with the switch contact piece 77, which latter is electrically connected through a flexible conductor with the terminal 78, connecting through the branch 7 9 with the conductor '2.- The switch operating lever 70ais pivotally mounted at 86, being normally so held that the contacts 69 and 77 are in the position shown in dotted lines, but adapted to be actuated by the switch ,act1ia%magnet 81 and thereby caused to assume e position indicated in the full 'lines and illustrating the said contacts 69 and 77. Circuits 1., 2, corresponding to 1 and 2, lead from a second station (not sh wn) through connections corresponding to ihose already described and which it will be unnecessary again to enumerate, there .be-

- ing provided for the circuits similar switch contacts 69" and 77', contact screws 73 and- 76 and a'switch actuating magnet 81. g

In thenormal position of the switch lever the spring contacts 69 and 69 each touch the contact screws 7 3' and 73 respectively and offer through their elasticity, a sulficient re-si tance to the movement of the lever to maintain the same in its normal posi- 5 tion except when'the lever arm is attracted .by the switch actuating magnet 81 or 81..

When the lever. arm is attracted by either such actuating magnet the connection between the opposite switch contact and its screw is thereby brokenpthe other contact piece, however, being compressed sufiicientl y to return the'swltch arm to its normafilposi- The contacts 77 and 77' are normally separated from their corresponding contact screws, but are each brought into contact, with-its respective screw on the 'actuationf'of the oppositely arranged switch magnet, the 1 relation between the two sets of contacts being preferably such, however, that thecon- .tact at 69 or69 is always broken before the corresponding contact at 771'! 77 is made. This, as before,-pro vides .a main line or transmitting circuit from each station-tend a branch line or receiving circuit from each station with switch connectionsand a 3 switch actuating magnet for linesuih that-on ,theactuatien of the switch magnet corresponding, to "one line; the other line or transmittin ,circuitwill be broken ,,and-':ii'nmediately-t ereaften'its branch or receiving circuit, which is normally interrupted, will be closed.

The switch magnet 81 is energized'on the the battery 84 and the coil 83 is in series with andnormally interrupted by the coherer or imperfect contact '85, which will described;m'ore in detail. This is wit-hm the magnetic influence of the coil 86, which latter is in series with the secondary of the transforn'ier 71, and is accordinglyenergized therewith, onthe passage of electrical-undulations through the primary of the trans former. It will thus be seen that I have provided-in conjunction with the translating device,herein the magnetcoil 83,-a circuit containing the said translating device and an imperfect contact, which latter,when

, influenced by the energy of the transmitter circuit, sci-resin turn to cause energization of the said translating device;

In Fig. 16 I have shown a form of coherer which is adapted to carry out my invention, but to which particular construction my invention is in no wise limited. This coherer comprises a number of loose magnetic particles, such for example, as fine iron filings interposed between appropriate terminal plugs, suitably, and preferably adjustably mounted, within and along'the axis of the actuating coil or helix 86. I. have discovered that by a suitable selection of the materials composing this coherer and by a suitable design of the coil actuating the same, the loose, non-conductive contact of the particles, one upon the other, which normally interrupts the, circuit of which the same forms a part when the said articles are at restor in* an -unexcited .con'ition, is. transformed, when the actuating coil orhelix is energized, into an electrically conductive contact, and the eoherer circuit, which is normally incapable of transmitting an appreciable amount of energy, becomes a circuit of high, electrical conductivity and the venergy transmitted therethrough readily actuates a relay or other similar device. i

Referring again'to Fig. 11 the'manner in which the movementof the switch takes of the switch magplace underthe actuation net will now be evident.- On the transmission through the circuit- 1, 2, of electrical undulations of any character, undulations corresponding to the same are produced in the secondary of the transformer 7 1, the coherer actuating coil 86 is energized, the norma'lly interrupted .coherer circuit is com pleted through the coherer, the magnet coil 83 is excited and, by itsarmature, completes the switch magnet circuit, thereby attracttive.

' ing the switch lever arm. In series with the switch magnet circuit I have shown a conventional form of ta-pper 87, which may con veniently engage a stud or pin attached to the core-of the actuating coil 86 by means of which a de-coherer effect may be maintained so long as the switch magnet is energlzed.

As in the arrangement previously described, interposed between the primary of the transformer. 67 which is in themain circuit 1, 2, and the secondary of the step-up transformer 75, is a repeater 16 which I have shown in conventional diagrammatic form, and which maybe of any suitable design or construction, being adapt-ed to reproduce electrical undulations in the circuit containing the primary transformer 67 again in the secondary of the transformer 7 5 and preferably with increased intensity. This repeater herein shown consists of a magnetcoil in circuit with the secondary of the transformer 67 having an armature adapted to vary the pressure in a suitable form of carbon contact, varying thereby the current flowing in the primary circuit of transformer 75. The undulations in the. main line circuit 1, 2, being thus reproduced in the secondary of the transformer 75 are transmitted when the switch is in full line position shown, to the main line circuit 1, 2', through the branch or transmitting circuit 74;, 79, and thence to the distant station, the receiving circuit on the line 1, 2, having been already broken by the switch, and the coherer and its associated receiving apparatus having been rendered inopera- The switch shown is thus automatically responsive to the ordinary voice currents transmitted over telephone lines, orv to the slightest electric undulations in the line circuits, as Was the case 'with the arrangement previously described. The relaying of coherence is effected, and the switch: restored to its normal position.

It will be obvious that additional coherers may be employed in the transmitting or .branch circuits if desired, and that instead of the transmitting-circuits with their corresponding repeaters as shown, which I prefer in practice, other circuit connect-ions may be employed. It will also be apparent that when my invention is employed for purposes other than the specific one herein described, changes and modifications suitable to theloccasion may be made without departing from the spirit thereof.

' creased to a, relatively great amount on' its" circuits and the receiving circuits is the- 1 circuit from the station 3, and the latter 8.1198 and is normally hel 69 .and..72 maintained closed. When the crating magnets, consisting of the support- In Figs. 12 and 13 I have indicated a convenicnt means for adjusting the switch oping, magnet-carrying slide 88 suitably engaged by the adjusting screw 89, and in Fig. 14 have indicated the pivotal construction of the switch lever 70.

In Fig. 15 I have diagrammatically shown a construction by means of which a de-- coherence is, effected at periodic intervals only, during the energization' of the coherer actuating coil. The main relay circuit containing the battery 90 and the translating device 91, which may be any suitable elect-romotive device, is provided with a shunt circuit about the translating device including the de'-'coherer 87 and the electrically; controlled interrupter 92. The latter comprises the contact disk 93 normally locked in position by the armature of the electro-magnet 94 but adaptedto be released thereby on the energization of said magnet, and rotated through a suitable clock-work train, temporarily completing the shunt tapper circuit ut once a revolution through the revolving contact 95'and the wiper 96. By this means a periodically interrupted de-coherenceis effected. 1

As a sensitive responder .to' the .voicecaused current on the line circuit, other He vices may be'employed than the articular one shown. In connection with Figs. 11-16 and Figs. 18 and 19 I have representeddifferent forms of circuit arrangements wherein there is employed some form of anticoherer, which, as is well-known to those skilled in the-art, has the property of maintaininga relatively-low resistance during the passage of a direct current of low tension therethrough, but of having its resistance in-' excitation through the agency of electrical impulses of relatively hi h frequency and tension. Referring to Fig. 17, it will be seenijfrorn an inspection that the general circulting of the main line or transmitting same as in Fig. 11, and like numerals will be used todesignate corresponding parts. In the arrangement shown in Fig. 17, however, independent switches 97 and 97' are voice-caused currents in the transmitting by the voice-caused currents from the station 3. i

The switch lever. 97 is Cpivotally mounted by the excitation of the switch magnet 99, in the full'line position shown, so that the circuit betweenthe sprin contact ,7 7 and the screw contact 76 is broken and that between the contacts magnet 99 is 'deenergized the switch is automatically moved through any appropriate means, such as the spring 100 into its'reversc position indicated in dotted line, whereby the circuit at the contacts 69 and 73 is broken and that at the contacts 76 and 77 closed. The companion switch 97 operates in the same fashion to make and break like circuits similarly related to the opposite side of the line.

The switch magnet 99 is normally maintained energized by current-from the battery 101 included in the circuit therewith, the switch magnet circuit also including means for either stopping or sufiiciently de creasing the current flow therethrough to cause he release of the switch 97 and its movement under the influence of the spring 100 into its reversed position. Forthis purpose I have herein shown a form of anti coherer conventionally represented at -102.

This may be constructed in any of its usual and the One important advantage of the anti-coherer is its extreme sensitiveness and its capaeity'for self-restoration which renders Cgenerally "known operative forms, and

the repeating devices always in a .condition' etails thereof are herein unnecessary to respondto -voice-caused energy. This obviously avoids-"the 'iiecessityjfor any additional apparatus, such'as the tapper 87 shown in F ig. 11, to automatically restore the circuit to its normal condition. y

In circuit with'theanti-'coherer 102 is the secondary of the transformer 71, the

same being thereby placed in inductive relation to the side 2 of the main line circuit 1, 2', whereby on the receipt of the voicecaused telephonic currents from the station 7 3' there is caused to be communicated to the anti-coherer- 102 electric impulses sutficient in otential and frequency to change the con ition of the anti-coherer from one of relatively high conductivity to one of relatively low conductivity, thereby sufiiciently deenergizing the magnet 99 to'cause the latter to; release the switch. This, as in the case of the circuit arrangements previously described, interrupts the transmitting circuit from the station 3. and completesthe receiving circuit leading thereto throu h the branches 74 and 79. Under such con itions.

the voice currents generated at the station 3 are reproduced at station 3 through the intermediation of suitable repeating devices. During this transmission the transmitting circuit from the station 3, having' ,been already broken by'the switch, its anti-ooherer and the associated receiving apparatus are therefore unaffected -bv.. -any energization transmitted over the line from station 3" to station 3.

the station 3, the sell-restoring nti-coherer tion of relatively lowlconductivity and the magnet 99 thereby freshly energized moves On the cessation the voice energy from 102" in.stantly reassumes its original condi-' the switch 97 again to malre the transmitting branch of the line circuit 1, 2, and break the receiving branch 74, 79 thereof.

It voice energy is transmitted from the station 3 to the stationB the transmitting circuit of station 3' is immediately broken while its receiving circuit 7'1 and 79 is immediately made and the action previously described takes place in the reverse direction. The relation of the two contacts 69 and 77 are preferably such that the contact at 69 is broken before the contact at 77 is made. The circuit control is therefore automatically effected by the voice-currents themselves, the switch corresponding to'tnat terminal station toward which the voice energy is transmitted, being thrown through the medium of its controlling anti-coherer to break its transmitting circuit and place its receiving circuit in condition to receive the message. The anticoherer being instantly self-restoring, the apparatus is always in condition to reproduce the telephonic undulations in either direction immediately upon the cessation of the previous transmission, no matter in what direction such previous transmission has taken lace,

Obvlously an automatically or self-restore ing coherer, that is, one restored to its nor; mal condition of conductivity without the employment of extraneous restoring means, or any. form of auto, circuit-controller might be employed, it being merely important'as a practical advantage that the coherer, antlcoherer, or whatever other sensitive responder'may be employed, should be quickly and automatically restored to its normal condition of receptiveness to the telephone currents. a

A repeating station of the type described may be developed through a variety of circuit arrangements, In Fig. 18 I have shown a slight modification over the arrangemexit of Fig. 17, there being substituted'for the two-part switch 97, 97', which latter, during the period of inactivity .or no transmission, .is under the constant control.

of its normally energized switch-magnets, the single switch 7 0 similar to that shown in Fig. 11, which, during periods of activity, -is attracted by one or the otherof the oppositely arranged switch magnets 81 or 81, the latterbeing in anormally deenergized condition.

In the modification shown in Fig. 18. the

. transmitting and receiving circuits and the repeating circuits for the two terminal stations are substantially the same as those described in connection with Fig. 17. The circuit connections. for controlling the switch, however, resemble those illustrated in Fig. 11, save that the anti-coherer 102 is employed,'which" leaves the relay magnet 83 in a normally energized condition, the armainsta-ntly ture thereof ybeing so disposed as to normally break the controlling circuit for the magnet 81. (in the energization of the relay magnet 83, as shown at the left in connection with the magnet 83, instead of breaking the said circuit on the de'energization of the said relay magnet, as in the arrange. ment shown in Fig. 11.

cuit controlling switch which is especially adapted for the system herein described and particularly when an arrangement-such electro-magnetic, switch-controlling means is excited directly by the telephone currents -th-emselves, althou h thesaid switch may be employed efl'ective ly in connection with the system shown in Fi 17, or in connection with the other modified circuit-in arrangements described. As previous y stated, where the switch is intended to respond directly to the voice-caused impulses it is important to provide for the swltch a relatively low natural rate of vibration. It is alsoimporta-ntthat it should be light and mechanically capable of responding to the low energy telephone currents, and that the controlling magnet should be capable of quick" discharge in order that its full strength may be availed of under the rapidly alternatin telephone currents.

It :will e noted that inconnect'ion with trollin magnets of the telephone-receiver type, t at is, with initially magnetized pole pieces, while in-Figs. 8 and 19 the controlling magnet is; substantially free from initial magnetism, In either-case,however,. it is desirable that they should. be quick [acting to respond readily to-the alternating telephone currents.

'While the switch described in connection with Figs; 1-5 inclusive has a normally'low low'est'audible tone of the human vo'ice, ,I have shown in Figs. 19-21 a switchnc'onstruction which is of preferableformjn fulupon practical use. I

Referring to Figs. 19-21 the parts ofthe switch are represented as mounted upon a delicately andfsensitively supported by a pivot pin 105 mounted in jeweled cup bearmovement necessary with a minimum amount of friction and inertia. The upper bearing isshown adjustable b, meansci thumb screw. 10,7 and lock-nu 10B. switch controlling magnet109 is suitably supported upon the base face .a' thin,

In Figs. 19-21 Ihave shown a form of ciras. shown in Fig. 1 is employed, where the Figsfl, 6, 11, 17 and 18 I-have shown conrate of vibration, lower than that 01 the filling this and, other conditions attendant base 103 of insulating material. The switch arm .104 is a small piece of some light 0911- ductive' material, preferably aluminum, which is also shown as drilled out furthers. to' lighten the same. The switch arm is ings- 106, so that it may execute" the slight light armature 110, preferably a piece of soft, thin sheet iron secured to the (and of the switch arm.

The magnet coils are connected to the terminal binding posts 111 and 112 and are mounted upon ends of the horse shoe core 113 as close to the arn' ature as possible.v

form of adjustable screws-114 and 11.5 ad-.

justably mounted in posts116 and 117, and preferably tipped with platinum ends which cooperate with platinum contacts 118 upon the switch arm. The posts 116 and 117 are connectedrespectively to terminal posts 119 and 120. The switch arm 104 is normally held in contact with one of the contact screws, as shown with-screw 115, by means of a resilient restoring member, the same herein comprising a relatively long, fine, flexible wire 121, with one end resting in the V-shaped groove of an upturned ear ,122 (see Fig, 21) on the rear end of the switch arm, and the opposite end held fixed in a block 123 which may be slidably adjusted transverse the axis of wire in the fixed frame 124 by means of the fine differential adjusting screw 125,

The wire 121 is preferably of iridiumplatinum and so finely dimensioned as to exert a Very delicate restoring tendency upon the SWltCllgfiIII], while having a'rate of vibration less than that of the lowest tone of the human voice. Connect-ion may be made to the switch arm through the platinum wire 121,the sliding block 123 and the frame 122 by means of the lead wire 126' the the and binding post 127. By adjustin the restoring tendency 0 spring may be very delicately adjusted.

To obtain the best results and maintain the switch in perfect balance, the base103 is provided with leveling screws 128 and the spirit level 129.

In Figs. 22 and 23 I have shown diagrammaticallyv the circuit connections where a switch like that shown in Fi 19 is em ployed, the arrangement ofFig. 22 corre-, 'sponding to that previously described in connection with Figs'l, 6 and 8, -and that shown in Fig. 23 corresponding to the ar-' rangement illustrated in Fig. 18.

In Fig. 22'the main transmitting circuit of each station, for example station 3, after passing through theprimary of the transmitting coil 67 passes to the switch controlling magnet 109 and thence to the normally closed switch controlled contact- 115 at the oppopite switch 104. The same side 1 of the transmitting circuit is branched at 130 to form the receiving circuit, which branch leads to the secondary of the receiving coil- 75 and thence to the normally open switch controlled con-tact 11 1" of. the switch 104. The opposite side 2 of the circuit is permanently connected to the switch 104 through the platinum restoring spring 121. The opposite side of the circuit of station 3 is similarly connected and related to the switch 104.

With speech transmitted from..stat-ion 3 the-transmitting circuit of station 3 is immediately broken by the movement of the switch 104, this insuring the continuance of switch 104', in the position shown. The 'movement of switch 104 also makes the receiving circuit at station 3 through con-- tact 114. v

only di erence beingthat the voice-caused currents. from the sending station act directly to excite'the magnet 109 through the intervention of the anticoherer 102 and the relay magnet 83, as described in connection with Fig. 18.

It will be. obvious that, if desired,'a relay circuit might be employed in connection with the system illustrated in Figs. 1, 6, 8 or 22'; that is'to say, insteadofhaving the controlling magnet,which is energized by the telephone currents, actdirectly upon the switch, it might serve to'make or break a relay circuit, thereby energizing or deenergizipg 'a second electro-magnetic device, which latter, directly or indirectly, might operate the switch. In such event, the relay circuit might be a normally closed circuit, as in the case in the system shown in Fig. 19, 'orthe same might be normally open, as in the case of the system shown in Fig. 23.

This application is a continuatlon of my prior copending application, Serial No. 57,864, filed April 29, 1901 as to the subject matter disclosed in Figs. 1 to 10 inclusive, of Serial No. 133,336 filed December 1, 1902 asto the subject matter. disclosed in F1 s. 11 to- 16 inclusive, and of Serial No. 286, '83 filed November 9, 1905 as to the subject matter disclosed 111,.Figs. 17 and 18.'

While I hafve shown and described several slightly differingig forms of my invention for the sake of llust-rating the principles thereof, it will be is not limited either-in the details of con.- struction 'or relative'arrang'ement of parts,

its application as herein ill.ustrated,.'but that 'extensive departures may be made .fr'om the I described forms of the invention without departing from the spiritth'ereof.

,Claiins:

1. 'In; a telephone relay system, a two-wayrepeating device comprising-one or more repeating instruments and circuit controlling means'tlie latter controlled by sound-caused electric currents and so disposedas to vary,

establish and maintain the circuits to and,

In Fi 23 the same result is obtained, the

to the described embodiment thereof nor to from the repeating device in response to the direction of sound-transmission from the s ieaking to the listening station.

2. In a telephone relay system, a tavo-way repeating device, consisting of two lines leading to the relay, each line being split at the relay into two circuits, one leading to a relayreceiver, the other leading to a relay-transmitter, of repeating instruments properly connected with said circuits, and a circuit controlling device, operatively related to said circuits, adapted to be actuated by magnetic influences in said circuit and so disposed that sound-causedelectric currents in said circuit will vary, establish and'maintain appropriate circuit connect-ions to and from said two-Way repeating device reciprocally-to the direction of speech-transmission from station to station.

In a telephone system the combination with a telephone repeater normally out of repeating relation to said system of a voice actuated, circuit making and breaking device and circuit changing means controlled by the same for placing said repeater in repeating relation.

l. In a telephone system, the combination with telephone circuits, of a telephone repeater means responsive to sound-caused. electric currents for-changing the transmitting circuit relations and then maintaining the same changed relation.-

5. In a telephone relay system, a two-way repeating device comprising repeating means and circuit controlling means. the latter con.- trolled by sound caused electric currents and so disposed as to vary, establislrand maintain the circuits to and from the repeating device in response to the direction of sound transmission from the speaking to the listening station.

6. In a telephone relay system, a two-way repeating device and a"hnec1rc1nt leading from each station thereto, said repeating dc V168 including a circuit changing device for placing either station in suitable repeating communication with the other, according to the direction of sound, transmission, and means actuated b the voice currents in either line circuit or operating said circuit changing device,

.7. In a telephone relay system,a repeat ing station, terminal stations having line circuits leading to said repeating station,

a transmitting circuit and a receiving circuit for each line circuit at said repeating station, and means forautomatically breaking the receiving circuit from one station and makin -the corresponding transmittingcircuit on the passage of voice currents from the opposite terminal station.

' 8 Iii-a telephone system, the combination of a telephone repeater, a voice actuated cir- .cuit making and breaking device, and C11- .cuit changing meansicontrelled by the same.

9. In a telephone system, the combinatirm With a. telephone circuit, of means for generating and llransi'nitting voice-caused currents over said telephone circuit, a second circuit, and ineansactuated by said voicecaused currents for crmnecting said telephone circuit With said second circuit.

10. in a telephone circuit, the combinw tion. with a line circuit of a transmitter, a voice-actuated device associated with said line circuit at a point remote from'said transn'iitter, and a circuit changing device controlled by said voice-actuated device through the voice energy transmitted through said transmitter. p

11. A telephone apparat us of the class de scribed having means for reproducing telephonic speech, sounds or the like, alternately from one main line circuit into another main line circuit, consisting of an electromagnetic telephonic transmitter, induction coils, batteries and circuit connections,andelcctro magnetic apparatus actuated and controlled by the act ofspcalting into the transmitter at either sending station for automatically selecting or connecting the two main line circuits.

12. A telephone apparatus of the class set forth, for reproducing in one main line cir cuit, electric currents, vibrations or in'ipulscs corresponding to theoriginal electric currents, vibrations-or impulsesin the primary main line circuit, having in dupl cate electro-magnetic means for selecting and (2011 necting the main line circuits as required, in combination with electro-magnetic telephone transmitting apparatus operating to automatically. retransmit the telephonic messages from one circuit to another, the electro-magnetic means being actuated and controlled by the act of speaking into the .transmitting apparatus at either sending station. a

13. In a telephone repeater, the combination of an electro-magnetic line controlling device, an electrb-magnetic transmitting apparatus including induction coils, local batteries and. circuit connectors cooperating With one main line circuit, and a duplicate apparatus in a second main line circuit, the electromagnetic line controlling devices beingactuated by the act of speaking into the transmitting apparatus at either sending station for controlling the relation of the transmitting apparatus to the main line cir cuits'.

14. A telephone repeater characterized by an electromagnetic line controlling device, the coils Which'are included in-one main line circuit, an induction coil having its secondary coil normally open and connected by the operation of the controlling device to a second main line clrcuit, the primary coil of said induction .coil being included 111 a local circuit having a battery, an electromagnetic transmitter provided witha vari able contact or microphone, the coils of which are included in the main line circuit with the coils of the controlling device, the latter being actuated by speaking into the transmitter.

15. A telephone repeater including as a part thereof an electromagnetic. transmitter having a magnet with extended pole pieces surrounded by coils or helices included in a main line circuit, a vibrating diaphragm having an armature attached thereto and arranged in front of the said magnet, variable contacts or microphone parts also co operating with said dlaphragm and actuated by the-latter, in combination with an induction coil, the primary of which is in eluded in circuit with the variable contacts and a local battery, the secondary of the coil being automatically connectible to a second circuit.

16. In a telephone system, the combina tion with a maln line telephone circuit, of means for generating and transmitting voice-caused currents over said circuit, a'

second main line telephone circuit, and means actuated b said volee-caused currents for automatically connecting the two leading to a repeating station,

circuits.

17. In a telephone system, the combination with a main line telephone'circuit, of means for generating and transmitting voice-caused currents over said circuit, a second main line telephone circuit, and means actuatedlby said voice-caused currents for automatically and interchangeably connecting the two main line telephone circuits.

18. In a telephonic repeating system, the combination with two transmission-lines leading to a repeating station, of a repeating-relay for each line, eachrelay having its receiving-coils normally connected with one line and its transmitter adapted for the control of voice-currents in the other line, and c retro-magnetic switching mechanism 'controlled by said repeating-relays.-

19. In a telephonic repeating station, the combination with two transmission lines leading to a repeating station, of a repeating-relay for each line,'each' relay having its receiving coils normally connected with one line and its transmitter adapted for the control of voice-currents in the other line, and electro-magnetic switching mechanism controlled by said. repeating-relays.

20. In a telephonic repeating system, the combination with two transmission lines of a repeating-rela'y for each line, each relay having its receiving coils normally connected with its line and its transmitter adapted for the control of voice-currents in the other line, and

switching mechanism controlled by said repeating-relays.

21. 'In a telephonic repeating system, the combination with two transn'iission lines leading to a repeating station, of a repeating-relay for each line, each relay having its receiving coils normally connected with its line and its transmitter adapted for the control of voice-currents in the other line, and switching mechanism controlled by said repeating-relays.

22. In a telephonic repeating system, the combination with a pair of transmission lines terminating at'a repeating station, of a repeating-relay for each line, an induction coil for each repeating relay, the circuit for the primarcoil of each induction coil being controlled y the transmitter of one of said repeating-relays and the secondary .coil of each induction coil'being adapted for connection with one of said transmission lines but normally disconnected therefrom, and means whereby the passage of telephonic voice-currents from one line to its repeating relay causes a connection of the secondary coil of the associated induction coil with the other transmission line.

23. In a telephonic repeating system, the combination with a pair of transmission lines terminating at a repeating station, of a repeating-relay for each line, an induction coil for each repeatingrelay, the circuit for the primary coil of each induction coil bein controlled by the transmitter of one of said repeating relays, the secondary coil of each induction coil being adapted for connection with one of said transmission lines but normally disconnected therefrom, and means whereby the passage of telephonic voicecurrents from one line to its repeatii'ig-relay causes a connection of the secondary coil of the associated induction coil with the other transmission line and causes a break in the. connection between this other transmission line and the receiving coils of its repeating relay.

24. In a telephonic repeating system, the combination with a pair of transmission lines terminating at a repeating station, of a repeating relay for each line, transformer means for inductively transferring telephonic voice-currents from one line. to the other, the primary currents through said transformer means being controlled-by said repeating relays, the secondary winding of said transformer means being ada ited for connection with said transmission lines but normally disconnected therefrom, and means whereby the passage of telephonic voicecurrents from one line to its repeating relay causes the closure of a telephonic circuit in-- eluding said transformer means from the transmitter portion of said repeating relay to the other transmission line.

25. In a telephonic repeating system, the combination with a pair of transmission lines terminating ata repeating station, of

voice-caused currents in said line circuit for- "a repeating-relay for each line, transformer means forinductively transferring telcphonic voice-currents from one line to the other, the primary currents through said transformer means being controlled by said repeating relays, thesecondary windings of said transformer means being adapted for connection with said transmission lines but normally disconnected therefrom, and means whereby the passage of telephonic voicecurrents from one line to its repeating-relayv causes the closure of a telephonic circuit including said transformer means from the transmitter portion of said repeating relay to the other transmission line and causes a break in the connection between this other transmission line and the receiving coils of its repeating relay,

26. In a telephonic repeating system, the

combination with a pair of transmission" lines terminating at a repeating station, of a repeating relay for each line, transformer means for inductively transmitting telephonic voice-currents from one line to the other, the primary currents through said transformer means being controlled by said repeating relays, the secondary windings of said transformer means being adapted for connection with said transmission lines but normally disconnected therefrom, and means whereby the passage of telephonic voicecurrents from either line to its repeating relay causes the closure of a circuit from the secondary windings of said transformermeans to the other transmission line.

27. In telephonic repeating system, the

combination withv a pair of transmission lines terminating at a repeating station, of a repeating-relay for each lihe, transformer means for inductively transmitting telephonic voice-currents from one line to the other, the primary currents through said transformer means being controlled by said repeating relays, the secondary windings of said transformer means being adapted for connection with said transmission lines but normally disconnected therefrom, and means whereby the passage of telephonic voicecurrents from either line to its repeating re lay causes the closure of a circuit from the secondary windings of said transformer means to the othertransmission line and causes a break in the connection between this other transmission line and the receiving coils of its repeatingrela-y. r V p p 28. In a telephone system, a line circuit, a circuit-changing device, means for operating said circuit-changing device, and a circuit in inductive relation to said line circuit an'd adapted' to be energized by the actuating said operating means.

v 29. In ajtel-ephone relay system, a repeating station, a plurality of sending and receiving stations having each a line circuit 1 leading to said repeating station, a circuitchanging device at said repeating station for placing either sending and receiving station in suitable repeating communication with the other according to the direction of sound transmission, means for operating said circuit-changing device, and a circuit in inductive relation to each of said line circuits and adapted to be energized by voice-caused currents in the line circuit for operating said circuit-changing device.

.30. In a telephone relay system, the combination with a sending station and a receiving station, of a repeating station between the two, means for normally maintaining the circuits between said stations in such relation as to prevent the repeating of ,'the voice-caused currents from said send ing station to said receiving station, means for changing said circuits to permit the repeating of voice-caused currents transmitted from said sending station, and means inductively related to the line circuit for operating said circuit-changing means.

$31. In a telephone relay'system, a line cir cuit and a repeating device comprising repeating means, circuit-controlling means, and means inductively related to the line circuit and controlled by sound-caused electric, currents to operate said. circuit-com trolling means whereby the latter is caused to vary, establish and maintain the circuits to-and from the repeating device in response to the direction of sound t ansmission from the speaking to the listening station.

In a telephone relay system, a line circuit and a repeating device comprising repeating means, circuit-controlling means and means including an imperfect contact so controlled by sound-caused electric currents as to operate said circuit-controlling the circuits to and from the repeating device in response .to-the direction of sound transmission from the speaking to the listening station. i i i V 33. In a telephone system, a line circuit, a circuit-changing device, means. for operating said circuit-changing device, and means including an imperfect contact con! trolled by the voice-caused currents in'said line circuit for actuating said operating means.

3i. In a telephone system, a line circuit, a circuit-changing device, and means-including a resistance-varying device for oper-- ating said circuit-changing means, said means being controlled by the voice-caused currents upon theline. circuit.

35. In a telephone system, a line circuit, a circuit-changing device, means for operating said circuit-changing device, a circuit provided with a source of electrical energy or energizing said operating means, and

means for varying the energization' of said means whereby the latter is caused to vary operating means through. the voice-caused currents upon the line circuit.

36. In a telephone relay system, a repeating station, a plurality of sending and recciving stations having each a nne circuit leading to said repeating station, a circuitchanging device at said repeating station for placingcither sending and receiving :!;a- 'tion in.communication with the other according to the direction of sound transmission, means for ope-rating said circuit-changing device, a circuit having a source of electrical energy for-energizing said operating means, and means controlled by voice-caused currents-on. the linc circuitfor varying the energization thereof.

37. In a telephone relay system, the. combination with a sending station and a re- 'ceiving station, of a repeating station between the two, means for ,lnormally main taining the circuits between said stations in such relation as to prevent; the repeating of the voice-caused currents from said sending station to said receiving station, means for changing said circuits to permit the re; peating of voice-caused currents transmitted .from said sending station, a circuit rovided with a source of electrical energy or actuating said circuit-changing means, and

30 means controlled by the voice caused cur rents upon the line circuit for varying the energization thereof.

,38. In a telephone relay system, aline circuit, a repeating device comprisingrepeating means, circuit? controllin means, a circuit provided Withv a source 0 electrical energy for controlling said circuit-controlling means, and means controlled by the line circuit energy for varying the energization of said controlling circuit whereby the circuit-controlling means is caused. to vary the circuits. to and from the repeating device.

39. In a telephone system, a line circuit, a circuit-changing device, and means for operating said circuit changing device including an imperfect contact within the elec tro-magnetic influence of the currents flow ing in said line circuit.

40. In a telephone relay system, a line cirout]; and arepeating device comprising repeating means, circuit-controlling means, and animperfect contact within the electromagnetic influence of the line circuit energy and controlling said circuitcontrolling means, whereby the latter is caused to vary the circuits'to and'from the repeating device in response to the direction of sound transmission from the speakingto the listening .station.

41. In a telephone relay system, a twoway repeating device comprising circuit-controlling means, the latter controlled by sound-caused electric currents and so disposed as to vary, establish and maintain the circuits to and from the rel'ueating device in response to the direction 01' sound transmission from. the speaking to the listening station, and a separate repeating device for each station.

42. In a telephone relay system, the comb ation with terminal stations, ,of a repeatii station, a transmission. and receiving circuit and a repeating circuit for each terminal station, circuit-controlling means for. varying the circuits to and from the repeating device in accordance with sound transmission from the speaking to the listening station, said circuitcontrolling means being adapted to break the transmission circuit of the listening station before making the receiving circuit thereof.

d3. In a telephone system, at'elcphone circuit, a transmitter, circuit-changing means, and means including a circuit of variable conductivity controlled by energy from said transmitter for actuating said circuit-changing means.

I 44. In atelephone system, a telephone circuit, a transmitter, a circuit-changing device, and means including an imperfect contact for operatin said circuit-ohangin device.

45. In a te ephone system, a telep 10116 circuit, a transmitter, a circuit-changing device,-

an means including an imperfect contact controlled by energy from said transmitter for operating said circuit-changing device.

46. In a telephone relay system, a line circuit, a transmitting station and a repeating device comprising repeating means and cir cuit controlling means and means including an imperfect contact controlled by energy from said transmitting station to operate the direction of said circuit-controlling means whereby the latteris caused to vary the clrcuit-s to and from the repeating device in response to the direction of sound transmission from the speaking to the listening station.

47. In a telephone-system, a line circuit, a

circuit-changing device, means for operating said circuit-changing device, and means, in cluding an anti-coherer controlled by the voice-caused currents in said line circuit/for actuating said operating means;

48. In a telephone relay system, a line circuit, and a repeating device comprising repeating means and circuit controlling means and means including an anti-coherer so controlled by sound-caused, electric currents as to operate said circuit-controlling means, whereby the latter is causedto vary the circuits to and from the repeating-device in response to the direction of sound transmission from the speaking to the listening station.

49. In a telephone-system, a line circuit, a circuit-changing device, means for operatingsaid circuit-changing device, and means includin g a self rstormg, imperfect 'contact' 

